In order to operate a power system stably, supply and demand of power need to be matched. Therefore, power supply is generally controlled in accordance with power demand on the consumer side.
In contrast, the number of power generation methods using renewable energy, such as photovoltaic power generation and wind power generation, is on the increase recently. In these power generation methods, it is difficult to control the amount of power generation, and it is difficult to keep supply-and-demand balance of power using only a general method.
As a means for solving these problems, there is demand response that performs suppression of power demand and induction of power demand of consumer's devices using a signal from outside (for example, refer to PTL 1).
The consumer's devices that contribute to the entire power system in the foregoing demand response are, for example, heat pump-mounted devices, such as a water heater and an air conditioner. These devices consume a large amount of power per one device. Thus, these devices are regarded as being important as devices that certainly produce the effect of the demand response by increasing or decreasing power consumption in accordance with power supply.